This invention relates to the art of lubrication, and is particularly directed to a mixer for developing an air/oil/water mixture for delivery to saw guides.
Large circular wood saw blades are often provided with guides in the vicinity of the material being sawn to stabilize the blade, and to permit the use of thinner blades, which, having a smaller kerf, produce less waste. Saw guide lubrication has traditionally been accomplished by injecting large volumes of water into guide pads on either side of a moving saw blade, which causes the saw to "float" on a film of water. One such system is shown in U.S. Pat. No. 3,674,065.
The water creates many problems. The fuel value of the resulting sawdust is reduced; an excessive amount of water penetrates the lumber requiring additional time and energy in lumber drying; water enters bearings and other machine parts, creating additional maintenance problems; mill floors are constantly wet and thus are safety hazards. The water that runs off from the mill creates an environmental clean-up problem. All of these problems are serious; furthermore, water is not a good lubricant.
Recently developed saw lubricators utilize a film of oil for the purpose of lubrication and a small amount of water on demand for saw cooling. Both the Ukiah and Schurman systems utilize complex pumping and metering devices to achieve the proper ratio of oil, water and air onto the saws and guides.
The present invention provides a very simple and economical but yet effective saw guide lubrication system. The invention utilizes a device created by a VICTOR or other brand of burning tip, which is adapted to inject water into oil in the low pressure area of the device. The resulting emulsion of air, oil and water is easily carried through a simple valving arrangement to the saw guides.
The benefits of this system over existing systems are as follows:
1. Water consumption is reduced approximately 90 to 95%, resulting in a drier working environment, higher BTU value of sawdust, and reduced environmental clean-up problems.
2. An air-oil-water emulsion is used as the lubricant rather than air of water, allowing the saw guides to be operated with much tighter tolerances, resulting in more accurate sawing. The oil also insures that wood resin does not build up on the saw blade, thus creating additional heat.
3. The above claims are also made for the Schurman Machine and Ukiah Machine lubrication system. This invention, however, uniquely utilizes the device effect created by a readily available burning tip, to mix oil, air and water thoroughly in situ. Each ingredient is metered to the right proportion upstream of the mixing chamber. This invention avoids the need for pumps, computers or other exotic means of controlling the exact ratios of air, oil and water.
4. The invention is contained in a compact package that can be directly attached to the existing piece of equipment that it serves. By comparison, the other known systems, being bulky and requiring large floor space, sometimes have to be located at a distance from the equipment. This separation can cause the premixed oil, air and water to separate and defeat the purpose of the apparatus.
In view of the foregoing, it is an object of this invention to provide a saw guide lubrication system with a simple yet effective lubricant mixer capable of mixing oil, water and air in various proportions. A related object is to provide such a mixer that is small and inexpensive.
A lubricant mixer according to the present invention comprises means defining an outlet nozzle, means defining separate respective inlets for air, oil and water, a liquids mixer for mixing the oil and water, said mixer comprising a body having a central passage in communication with said oil inlet, and a plurality of outer passages in communication with said water inlet, said mixer extending into said outlet nozzle, and means defining a chamber surrounding said mixer and in communication with both said air inlet and said outlet nozzle.